Color conversion sheet and backlight unit including the same

Patent metadata

Field	Value
Publication number	US-12291015-B2
Application number	US-202318567540-A
Country	US
Kind code	B2
Filing date	Jul 24, 2023
Priority date	Aug 18, 2022
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

A color conversion sheet according to the present invention includes a first wavelength conversion layer in which an organic phosphor is dispersed in a resin matrix, a first phosphor diffusion barrier layer positioned on one surface of the first wavelength conversion layer, and an adhesive layer positioned on one surface of the first phosphor diffusion barrier layer, wherein a Hildebrand solubility parameter of the first phosphor diffusion barrier layer satisfies a predetermined relationship between a Hildebrand solubility parameter of the resin matrix of the first wavelength conversion layer and a Hildebrand solubility parameter of a solvent contained in the first phosphor diffusion barrier layer, thereby resolving problems of changes in luminance characteristics and color change.

First claim

What is claimed is:

1. A color conversion sheet comprising:
a first wavelength conversion layer in which an organic phosphor is dispersed in a resin matrix;
a first phosphor diffusion barrier layer positioned on one surface of the first wavelength conversion layer; and
an adhesive layer positioned on one surface of the first phosphor diffusion barrier layer,
wherein the first phosphor diffusion barrier layer is formed from a composition containing a solvent having a Hildebrand solubility parameter according to Equation 1 below:
| P 1 −S 2|>2 MPa 1/2   (Equation 1)

P1: Hildebrand solubility parameter of the resin matrix of the first wavelength conversion layer
S2: Hildebrand solubility parameter of the solvent included in the first phosphor diffusion barrier layer.

2. The color conversion sheet of claim 1 , wherein the first phosphor diffusion barrier layer further comprises a thermosetting or thermoplastic organic compound that has a Hildebrand solubility parameter according to Equation 2 below:
| P 1− P 2|>2 MPa 1/2   (Equation 2)

P1: Hildebrand solubility parameter of the resin matrix of the first wavelength conversion layer
P2: Hildebrand solubility parameter of the organic compound included in the first phosphor diffusion barrier layer.

3. The color conversion sheet of claim 1 , wherein a thickness of the first phosphor diffusion barrier layer is 0.01 to 10 μm.

4. The color conversion sheet of claim 1 , having a color coordinate change on both x-axis and y-axis within +0.0015 after treatment for 480 hours at 70° C.

5. The color conversion sheet of claim 1 , wherein the resin matrix contains at least one of an ester-based resin, an olefin-based resin, an acrylic-based resin, an ether-based resin, an urethane-based resin, a carbonate-based resin, or an imide-based resin.

6. The color conversion sheet of claim 1 , wherein the resin matrix has a glass transition temperature of 50 to 140° C.

7. The color conversion sheet of claim 1 , wherein the organic phosphor of the first wavelength conversion layer does not migrate into the phosphor diffusion barrier layer.

8. The color conversion sheet of claim 1 , wherein the first phosphor diffusion barrier layer has a visible light transmittance of 70% or more.

9. The color conversion sheet of claim 1 , further comprising a substrate positioned on at least one surface of the first wavelength conversion layer or the adhesive layer.

10. The color conversion sheet of claim 1 , further comprising:
a second phosphor diffusion barrier layer positioned on the adhesive layer; and
a second wavelength conversion layer positioned on the second phosphor diffusion barrier layer and having an organic phosphor dispersed in a resin matrix.

11. The color conversion sheet of claim 10 , wherein the second wavelength conversion layer contains an organic phosphor having the same or different color as that of the organic phosphor dispersed in the first wavelength conversion layer.

12. The color conversion sheet of claim 10 , wherein the second phosphor diffusion barrier layer is formed from a composition containing a solvent having a Hildebrand solubility parameter according to Equation 1 below:
| P 1 −S 2|>2 MPa 1/2   (Equation 1)

P1: Hildebrand solubility parameter of the resin matrix of the second wavelength conversion layer
S2: Hildebrand solubility parameter of the solvent included in the second phosphor diffusion barrier layer.

13. The color conversion sheet of claim 10 , wherein the second phosphor diffusion barrier layer further comprises a thermosetting or thermoplastic organic compound that has a Hildebrand solubility parameter according to Equation 2 below:
| P 1− P 2|>2 MPa 1/2   (Equation 2)

P1: Hildebrand solubility parameter of the resin matrix of the second wavelength conversion layer
P2: Hildebrand solubility parameter of the organic compound included in the second phosphor diffusion barrier layer.

14. A backlight unit comprising the color conversion sheet according to claim 1 .

Assignees

• Toray Advanced Mat Korea Inc

Inventors

• Jin Sang Woo
• Park Jun Woo
• Oh Ji Whan

Classifications

• B32B2250/05

  5 or more layers · CPC title

• B32B27/40

  comprising polyurethanes · CPC title

• B32B27/36

  comprising polyesters · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title

• B32B27/30

  comprising vinyl {(co)polymers; comprising acrylic (co)polymers} · CPC title